Comparing Waiting Lines
a. The values listed below are waiting times (in minutes) of customers at the Jefferson Valley Bank, where customers enter a single waiting line that feeds three teller windows. Construct a 95% confidence interval for the population standard deviation σ.
b. The values listed below are waiting times (in minutes) of customers at the Bank of Providence, where customers may enter any one of three different lines that have formed at three teller windows. Construct a 95% confidence interval for the population standard deviation σ.
c. Interpret the results found in parts (a) and (b). Do the confidence intervals suggest a difference in the variation among waiting times? Which arrangement seems better: the single-line system or the multiple-line system?
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
ELEMENTARY SATISTICS IA
- AP1.2 A child is 40 inches tall, which places her at the 90th percentile of all children of similar age. The heights for children of this age form an approximately Normal distribution with a mean of 38 inches. Based on this information, what is the standard deviation of the heights of all children of this age? 0.20 inches (c) 0.65 inches (e) 1.56 inches 0.31 inches (d) 1.21 inchesarrow_forwardAP1.1 You look at real estate ads for houses in Sarasota, Florida. Many houses range from $200,000 to $400,000 in price. The few houses on the water, however, have prices up to $15 million. Which of the following statements best describes the distribution of home prices in Sarasota? The distribution is most likely skewed to the left, and the mean is greater than the median. The distribution is most likely skewed to the left, and the mean is less than the median. The distribution is roughly symmetric with a few high outliers, and the mean is approximately equal to the median. The distribution is most likely skewed to the right, and the mean is greater than the median. The distribution is most likely skewed to the right, and the mean is less than the median.arrow_forwardDuring busy political seasons, many opinion polls are conducted. In apresidential race, how do you think the participants in polls are generally selected?Discuss any issues regarding simple random, stratified, systematic, cluster, andconvenience sampling in these polls. What about other types of polls, besides political?arrow_forward
- Please could you explain why 0.5 was added to each upper limpit of the intervals.Thanksarrow_forward28. (a) Under what conditions do we say that two random variables X and Y are independent? (b) Demonstrate that if X and Y are independent, then it follows that E(XY) = E(X)E(Y); (e) Show by a counter example that the converse of (ii) is not necessarily true.arrow_forward1. Let X and Y be random variables and suppose that A = F. Prove that Z XI(A)+YI(A) is a random variable.arrow_forward
- Glencoe Algebra 1, Student Edition, 9780079039897...AlgebraISBN:9780079039897Author:CarterPublisher:McGraw Hill